Fuel is a major portion of the total cost of ownership for a number of hydraulic machines, such as, for example, hydraulic mining excavators or shovels. As such, hydraulic systems with greater efficiency may offer a competitive advantage. Typically, however, these systems are not optimized for energy efficiency. For example, on some hydraulic mining shovels, there are four main pumps. One pump powers clam cylinders, while travel motors are powered by one pump for each side of the machine. Yet, regardless of the work cycle segment being performed, when an operator actuates the pedal for propulsion, all four pumps get the same command and, typically, this results in pressurized oil being provided at a much higher rate than is necessary.
European Patent Application No. EP 2746466 to Cugati et al. discloses a system and method for providing hydraulic power to a plurality of hydraulic circuits of a machine. In particular, the disclosed system allows assigning individual hydraulic pumps to different hydraulic circuits of the hydraulic system. As such, the system nearly eliminates all flow sharing between the different hydraulic circuits to avoid pressure drop losses.
As should be appreciated, there is a continuing need to provide greater energy efficiency in the area of hydraulic machinery. The present disclosure is directed to such an endeavor.